A kind of bead protection rubber for all-steel giant engineering machinery radial tire and preparation method thereof

Abstract

The present application relates to the technical field of tire rubber preparation, and specifically discloses a rubber for a radial tire of all-steel giant engineering machinery and a preparation method thereof; a rubber for a radial tire of all-steel giant engineering machinery, comprising the following raw materials: natural rubber, butadiene rubber, carbon black, zinc oxide, stearic acid, antioxidant, protective wax, glass short fiber, softener, homogenizer, sulfur, accelerator, anti-scorch agent, anti-vulcanization reversion agent; its preparation method is: natural rubber, butadiene rubber, and carbon black are mixed to obtain a first-stage mixed masterbatch; zinc oxide, stearic acid, antioxidant, protective wax, glass short fiber, softener, and homogenizer are added, and a second-stage mixed masterbatch is obtained through mixing; finally, sulfur, accelerator, anti-scorch agent, and anti-vulcanization reversion agent are added, and a final mixed rubber is obtained through mixing; the rubber has the advantages of small hysteresis loss, low compression heat generation, high modulus, good vulcanization flatness, high tensile strength, good wear resistance, and resistance to heat and oxygen aging.

Description

Technical Field

[0001] The present application relates to the technical field of tire rubber preparation, and in particular to a bead protection rubber for all-steel giant engineering machinery radial tire and a preparation method thereof. Background Art

[0002] All-steel giant construction machinery radial tires are mainly used on large mining dump trucks. Their working environment is very harsh, the road surface is often accompanied by gravel potholes, and the vehicle load can reach more than 300 tons. This requires all-steel giant construction machinery radial tires to have excellent performance in tensile strength, heat generation, wear resistance, and anti-aging performance.

[0003] The bead guard is the only part of the tire that is in direct contact with the vehicle. It will be subjected to repeated extension, compression deformation and friction when the vehicle is moving. Therefore, the bead guard should have high tensile strength, hardness, wear resistance, resistance to thermal oxygen aging and low heat generation. In addition, during the vulcanization process, the bead guard is in direct contact with the heating device. Compared with the rubber inside the tire, the vulcanization time starts earlier and over-vulcanization occurs more easily. Therefore, the bead guard requires a longer vulcanization flat period.

[0004] Therefore, how to prepare a rubber for protecting the sub-mouth, which has the advantages of small hysteresis loss, low compression heat generation, high modulus, good vulcanization flatness, high tensile strength, good wear resistance, and resistance to heat and oxygen aging, is a problem to be solved. Summary of the invention

[0005] In order to prepare a bead guard rubber which has the advantages of small hysteresis loss, low compression heat generation, high modulus, good vulcanization flatness, high tensile strength, good wear resistance, and resistance to heat and oxygen aging, the present application provides a bead guard rubber for an all-steel giant engineering machinery radial tire and a preparation method.

[0006] In the first aspect, the present application provides a bead protection rubber for an all-steel giant engineering machinery radial tire, which adopts the following technical solution:

[0007] A rubber bead protector for an all-steel giant engineering machinery radial tire, the rubber bead protector comprising the following raw materials in parts by weight: 40-60 parts of natural rubber, 43-65 parts of butadiene rubber, 60-70 parts of carbon black, 2-3 parts of zinc oxide, 1-2 parts of stearic acid, 3-6 parts of antioxidant, 0.5-1 part of protective wax, 4-5 parts of short glass fiber, 2-4 parts of softener, 2-4 parts of homogenizer, 2-4 parts of sulfur, 1-2 parts of accelerator, 0.2-0.5 parts of anti-scorch agent and 0.5-1 parts of anti-reversion agent.

[0008] By adopting the above technical scheme, carbon black, zinc oxide and glass staple fibers are combined to increase the tensile strength and heat aging resistance of natural rubber and butadiene rubber, and make natural rubber and butadiene rubber have the advantages of small hysteresis loss, low compression heat generation and high modulus; combined with antioxidants and protective waxes, the wear resistance and heat-oxidative aging resistance of natural rubber and butadiene rubber can be improved; combined with a homogenizer, the uniformity of mixing of natural rubber and butadiene rubber can be improved; combined with accelerators and softeners, the crosslinking density of natural rubber and butadiene rubber during the vulcanization process can be increased, and the crosslinking network structure can be improved, thereby further improving the mechanical strength and aging resistance of the finished product; combined with anti-vulcanization reversion agents and anti-scorching agents, the sub-mouth protective rubber is not prone to over-vulcanization during the vulcanization process, so that the sub-mouth protective rubber has a longer vulcanization flat period, and the sub-mouth protective rubber is consistent with the vulcanization degree inside the tire.

[0009] Preferably, the butadiene rubber comprises the following raw materials in parts by weight: 40-50 parts of low-cis polybutadiene rubber and 3-5 parts of liquid polybutadiene rubber.

[0010] By adopting the above technical scheme, low cis polybutadiene rubber and liquid polybutadiene rubber are matched to improve the self-adhesiveness of the rubber compound and at the same time improve the crosslinking density of the finished spigot protective rubber, thereby improving the mechanical strength and heat aging resistance of the finished spigot protective rubber.

[0011] Preferably, the antioxidant comprises the following raw materials in parts by weight: 1-2 parts of antioxidant 4020, 1-2 parts of antioxidant RD, and 1-2 parts of cerium stearate.

[0012] By adopting the above technical solution, the heat-oxidation aging resistance of the finished product spout protective glue can be improved, and the wear resistance of the finished product spout protective glue can be improved.

[0013] Preferably, the short glass fibers are rubber-impregnated modified short glass fibers.

[0014] By adopting the above technical scheme, the glass staple fibers are modified by rubber, the compatibility of the glass staple fibers with natural rubber and butadiene rubber is improved, and the glass staple fibers are more stably dispersed in the sub-mouth protective rubber, thereby utilizing the higher strength of the glass staple fibers to improve the mechanical strength of the finished sub-mouth protective rubber.

[0015] When large mining dump trucks pass through gravel pits, gravel, sand and other materials are often easily splashed. The use of rubber impregnated modified glass staple fibers can make the finished sub-mouth protective rubber less likely to be scratched by gravel and sand. In combination with protective wax and stearic acid, the surface flatness of the sub-mouth protective rubber can be further improved, and muddy water mixed with gravel and sand can be avoided from adhering to the surface of the finished sub-mouth protective rubber. This protects the sub-mouth protective rubber from aging due to moisture, and from being scratched by particles, which affects its mechanical strength and service life.

[0016] Preferably, the rubber impregnated modified glass staple fiber is prepared by the following method:

[0017] Step I: Dip one end of the glass fiber into the ethyl cellulose solution, then dip the surface of the cutter into the ethyl cellulose solution, and then cut the glass fiber. After cutting, dry quickly to obtain glass fiber chopped strands with a length of 3-6 mm.

[0018] Step II: soaking the chopped glass fibers in water containing amino-modified elastic particles, filtering out the water, heating the chopped glass fibers loaded with amino-modified elastic particles to 80-90° C. for heat treatment, and then cooling to obtain loaded glass short fibers;

[0019] Step III: spraying acrylic resin melt evenly on the surface of the carrier glass short fiber, the weight ratio of the carrier glass short fiber to the acrylic resin melt is 1:0.1-0.4, spraying EPDM rubber evenly after drying, the weight ratio of the carrier glass short fiber to the EPDM rubber is 1:0.2-0.5, and obtaining the finished product after drying.

[0020] By adopting the above technical scheme, glass fiber filaments, ethyl cellulose solution, amino-modified elastic particles, acrylic resin melt, and EPDM rubber are matched, so that the circumference of the glass staple fiber is loaded with amino-modified elastic particles, while the end is not loaded with amino-modified elastic particles, so that the glass fiber chopped strands gradually change from filaments to ellipsoids, thereby increasing the contact area between the rubber-impregnated modified glass staple fiber and the natural rubber and butadiene rubber; and the viscosity of the acrylic resin melt facilitates the attachment of the EPDM rubber to the surface of the loaded glass staple fiber by utilizing the viscosity of the acrylic resin melt, and at the same time, the carboxyl groups in the acrylic resin melt and the amino groups on the surface of the amino-modified elastic particles can further improve the adhesion stability of the EPDM rubber on the surface of the glass staple fiber, and the compatibility of the EPDM rubber with the natural rubber and butadiene rubber during the mixing process is utilized to improve the compatibility of the rubber-impregnated modified glass staple fiber with the natural rubber and butadiene rubber, and the larger contact area, better compatibility and higher strength of the glass staple fiber can be used to improve the mechanical strength and tear resistance of the finished spout protective rubber, thereby extending the service life of the spout protective rubber.

[0021] Glass fiber yarn, amino-modified elastic particles, water immersion treatment and heating operation are coordinated. Ethyl cellulose solution is attached to both ends of the glass fiber yarn. Since ethyl cellulose is insoluble in water, the ends of the glass staple fibers are capped with ethyl cellulose and then immersed in water containing amino-modified elastic particles. The hydroxyl groups on the peripheral surface of the glass staple fibers are used to attract the amino-modified elastic particles to be adsorbed around the glass staple fibers. Then, the amino-modified elastic particles are subjected to heating treatment to make them adhere to the peripheral surface of the glass staple fibers. However, due to the hydrophobicity of ethyl cellulose, the amino-modified elastic particles are not easy to adhere to the ends of the glass staple fibers. After the amino-modified elastic particles are attached to the peripheral surface of the filamentous glass staple fibers, they gradually tend to be round particles, which increases the contact area between the rubber-impregnated modified glass staple fibers and the natural rubber and butadiene rubber, improves the structural density of the finished sub-mouth protective rubber, and thus improves the mechanical strength of the finished sub-mouth protective rubber.

[0022] Amino modified elastic particles, acrylic resin melt and EPDM rubber are matched together. The elasticity of the elastic particles in the amino modified elastic particles is combined with the elasticity of the EPDM rubber, so that the rubber guard at the sub-mouth has a better elastic buffering effect. When squeezing occurs when passing through potholes, its elasticity can buffer the pressure and quickly recover on flat roads, so that the rubber guard at the sub-mouth has a longer service life. Its elasticity can also resist the impact of gravel and sand, and try to avoid the problem of scratches and pits caused by gravel, sand and other materials impacting the rubber guard at the sub-mouth during the operation of large vehicles, thereby extending the service life of the rubber guard at the sub-mouth on harsh roads.

[0023] The rubber impregnated modified glass staple fiber, protective wax and stearic acid are combined, and the water-blocking property of the acrylic resin film in the rubber impregnated modified glass staple fiber, combined with the hydrophobic effect of the protective wax and the water-isolating effect of stearic acid, can improve the water resistance of the sub-mouth protective rubber, and try to avoid mud and water on bumpy and muddy roads from adhering to the surface of the sub-mouth protective rubber, causing aging of the sub-mouth protective rubber and affecting the service life of the sub-mouth protective rubber.

[0024] Preferably, the amino-modified elastic particles are prepared by the following method:

[0025] The swellable chitosan is placed in dilute acetic acid and stirred to dissolve to obtain a solution; then EVA particles are added, the weight ratio of the solution to the EVA particles is 1:0.05-0.2, and the mixture is evenly dispersed to obtain a swellable chitosan solution;

[0026] Weigh the polyimide resin particles and soak them in the swelling chitosan solution, then take out the polyimide resin particles and dry them to obtain the finished product.

[0027] By adopting the above technical scheme, polyimide resin, swellable chitosan and EVA particles are matched, and the viscosity of chitosan liquid is utilized to facilitate the chitosan liquid to adhere to the surface of polyimide resin particles. When the temperature is increased, the EVA particles gradually melt, further improving the adhesion stability of the amino-modified elastic particles on the surface of the glass staple fiber, so that the contact area between the loaded glass staple fiber and the rubber is larger than that of the filamentary glass staple fiber, thereby improving the structural density of the sub-mouth protective rubber, thereby improving the mechanical strength and scratch resistance of the sub-mouth protective rubber.

[0028] Polyimide resin particles, swellable chitosan liquid, acrylic resin melt, and EPDM rubber are matched. The swellable chitosan will only swell but not dissolve during immersion in water, while the amino and hydroxyl groups on the surface of the amino-modified elastic particles are easily attracted and connected with the hydroxyl groups on the surface of the glass fiber chopped strands by hydrogen bonds, thereby facilitating the amino-modified elastic particles to be close to the surface of the glass fiber chopped strands. As the temperature rises, the amino-modified elastic particles are stably attached to the surface of the glass fiber chopped strands. However, the polyimide resin has a high melting point and will not The polyimide resin particles dissolve during the heating and vulcanization process, so that they always remain in granular form and adhere to the surface of the glass staple fiber. The elasticity of the polyimide resin particles provides an elastic buffering effect for the spout rubber and ensures that the loaded glass staple fiber has a larger specific surface area. The EPDM rubber is easily softened and hot-melted during the vulcanization process, thereby improving the compatibility of the rubber-impregnated modified glass staple fiber with natural rubber and butadiene rubber. Combined with a larger contact area, the cross-linking structure density of the spout rubber is further improved, thereby improving the mechanical strength and aging resistance of the spout rubber.

[0029] Preferably, the accelerator comprises the following raw materials in parts by weight: 0.5-1 part of accelerator NS, 0.5-1 part of accelerator DZ.

[0030] By adopting the above technical solution, the accelerator NS and the accelerator DZ cooperate with each other, which can increase the crosslinking density of the sub-mouth protective glue and improve the crosslinking network structure, thereby increasing the mechanical strength of the sub-mouth protective glue and extending the service life of the sub-mouth protective glue.

[0031] Preferably, the homogenizer is homogenizer 40-MSF.

[0032] By adopting the above technical solution, the mixing uniformity between natural rubber and butadiene rubber, carbon black, short glass fibers and other fillers can be improved.

[0033] In a second aspect, the present application provides a method for preparing a bead protection rubber for an all-steel giant engineering machinery radial tire, which adopts the following technical solution:

[0034] A method for preparing a bead protection rubber for an all-steel giant engineering machinery radial tire comprises the following steps:

[0035] S1. After mixing natural rubber, butadiene rubber and carbon black, the mixture is mixed, discharged, film is prepared and allowed to stand to obtain a mixed masterbatch;

[0036] S2, mixing zinc oxide, stearic acid, antioxidant, protective wax, short glass fiber, softener, homogenizer and the first-stage mixed masterbatch prepared in S1, and preparing the second-stage mixed masterbatch through mixing, debonding, film preparation and standing;

[0037] S3, the second stage mixed masterbatch is subjected to internal mixing, sulfur, accelerator, anti-scorch agent, anti-vulcanization reversion agent are added after the rubber is broken, and the finished product of the spigot protection rubber is obtained through rubber refining, rubber discharge, film preparation, and standing.

[0038] By adopting the above technical scheme, the finished product of the spout protective rubber has the advantages of small hysteresis loss, low compression heat generation, high modulus, good vulcanization flatness, high tensile strength, good wear resistance, and resistance to heat and oxygen aging.

[0039] In summary, this application has the following beneficial effects:

[0040] 1. Carbon black, zinc oxide and glass staple fibers can be combined to increase the tensile strength and heat aging resistance of natural rubber and butadiene rubber, and make natural rubber and butadiene rubber have the advantages of small hysteresis loss, low compression heat generation and high modulus; combined with antioxidants and protective waxes, the wear resistance and heat-oxidative aging resistance of natural rubber and butadiene rubber can be improved; combined with homogenizers, the uniformity of mixing of natural rubber and butadiene rubber can be improved; combined with accelerators and softeners, the crosslinking density of natural rubber and butadiene rubber during the vulcanization process can be increased, and the mechanical strength and aging resistance of the finished product can be further improved by increasing the density of the crosslinking network structure; combined with anti-vulcanization reversion agents and anti-scorching agents, the sub-mouth protective rubber will not be over-vulcanized when it contacts the heating device, so that the sub-mouth protective rubber has a longer vulcanization flat period, and the sub-mouth protective rubber is consistent with the vulcanization degree inside the tire.

[0041] 2. The swelling chitosan, EVA particles, polyimide resin particles, glass fiber chopped strands, water immersion treatment and temperature-raising heat treatment are coordinated. The viscosity of the swelling chitosan after being dissolved in dilute acetic acid is used to load the EVA particles on the surface of the polyimide resin particles. As the amino-modified elastic particles are soaked in water, the amino and carboxyl groups in the swelling chitosan are easily attracted and connected with the hydroxyl groups on the peripheral surface of the glass fiber chopped strands, so that the amino-modified elastic particles are close to the peripheral surface of the glass fiber chopped strands. As the temperature rises and the heat treatment is performed, the EVA particles are gradually hot-melted, and the amino-modified elastic particles are bonded to the peripheral surface of the glass fiber chopped strands, so that the amino-modified elastic particles cover the periphery of the glass fiber, and the filamentous structure of the glass fiber is modified to a circular structure, thereby increasing the contact area between the rubber-impregnated modified glass fiber and the natural rubber and butadiene rubber, thereby improving the cross-linking structure density of the sub-mouth protective rubber, so that the sub-mouth protective rubber has higher mechanical strength and longer service life. DETAILED DESCRIPTION

[0042] The present application is further described in detail below with reference to the embodiments.

[0043] Preparation Example of Amino-modified Elastic Particles

[0044] Preparation Example 1: Amino-modified elastic particles are prepared by the following method:

[0045] The swellable chitosan was placed in 2% dilute acetic acid and stirred to dissolve to obtain a solution, and then 0.1 kg of EVA particles were added to 1 kg of the solution. The EVA particles had a particle size of 40 mesh and a melting point of 80°C. After being evenly dispersed, a swellable chitosan solution was obtained.

[0046] 1 kg of polyimide resin particles were weighed and immersed in 5 kg of swellable chitosan solution, wherein the particle size of the polyimide resin particles was 20 meshes. The polyimide resin particles were then filtered out and dried to obtain a finished product.

[0047] Preparation Example 2: This preparation example differs from Preparation Example 1 in that:

[0048] The swellable chitosan was placed in 2% dilute acetic acid and stirred to dissolve to obtain a solution, and then 0.05 kg of EVA particles with a particle size of 40 mesh were added to 1 kg of the solution, and the EVA particles were evenly dispersed to obtain a swellable chitosan solution;

[0049] 1 kg of polyimide resin particles were weighed and immersed in 5 kg of swellable chitosan solution, wherein the particle size of the polyimide resin particles was 20 meshes. The polyimide resin particles were then filtered out and dried to obtain a finished product.

[0050] Preparation Example 3: This preparation example differs from Preparation Example 1 in that:

[0051] The swellable chitosan was placed in 2% dilute acetic acid and stirred to dissolve to obtain a solution, and then 0.2 kg of EVA particles with a particle size of 40 mesh were added to 1 kg of the solution, and the EVA particles were evenly dispersed to obtain a swellable chitosan solution;

[0052] 1 kg of polyimide resin particles were weighed and immersed in 5 kg of swellable chitosan solution, wherein the particle size of the polyimide resin particles was 20 meshes. The polyimide resin particles were then filtered out and dried to obtain a finished product.

[0053] Example of Preparation of Rubber-Impregnated Modified Short Glass Fibers The EPDM rubber in the following raw materials was purchased from Chengdu Senfa Rubber & Plastic Co., Ltd.; other raw materials and equipment were commercially available.

[0054] Preparation Example 4: Rubber impregnated modified glass short fibers are prepared by the following method:

[0055] Step I: one end of the glass fiber is dipped in ethyl cellulose solution, the ethyl cellulose solution is a 1% ethyl cellulose ethanol solution, the ethanol is anhydrous ethanol with a mass fraction of 99%, and the length of the end of the glass fiber dipped in ethyl cellulose is 0.1 mm; then the surface of the cutter is dipped in ethyl cellulose solution, and then the glass fiber is cut, and the glass fiber is quickly dried after cutting to obtain 4 mm long glass fiber chopped strands;

[0056] Step II: 1 kg of glass fiber chopped strands are placed in 5 kg of water containing amino-modified elastic particles, 2 kg of amino-modified elastic particles are placed in the 5 kg of water, and the amino-modified elastic particles are selected from the amino-modified elastic particles prepared in Preparation Example 1, and then the water is filtered out, and the glass fiber chopped strands loaded with amino-modified elastic particles are heated to 85° C. for heat treatment for 5 min, and then cooled to obtain loaded glass short fibers;

[0057] Step III: 0.3 kg of acrylic resin melt is evenly sprayed on the surface of 1 kg of loaded glass short fibers. The acrylic resin melt is obtained by hot melting thermoplastic acrylic resin solid particles. After drying, 0.4 kg of EPDM rubber is evenly sprayed on the surface. The EPDM rubber is EPDM rubber particles with a particle size of 40 mesh. After drying, a finished product is obtained.

[0058] Preparation Example 5: This preparation example differs from Preparation Example 4 in that:

[0059] Step I: one end of the glass fiber is dipped in ethyl cellulose solution, the ethyl cellulose solution is a 1% ethyl cellulose ethanol solution, the ethanol is anhydrous ethanol with a mass fraction of 99%, and the length of the end of the glass fiber dipped in ethyl cellulose is 0.2 mm; then the surface of the cutter is dipped in ethyl cellulose solution, and then the glass fiber is cut, and the glass fiber is quickly dried after cutting to obtain 3 mm long glass fiber chopped strands;

[0060] Step II: 1 kg of glass fiber chopped strands are placed in 5 kg of water containing amino-modified elastic particles, 2 kg of amino-modified elastic particles are placed in the 5 kg of water, and the amino-modified elastic particles are selected from the amino-modified elastic particles prepared in Preparation Example 2, and then the water is filtered out, and the glass fiber chopped strands loaded with amino-modified elastic particles are heated to 80° C. for heat treatment for 5 min, and then cooled to obtain loaded glass short fibers;

[0061] Step III: spray 0.1 kg of acrylic resin melt evenly on the surface of 1 kg of loaded glass short fibers, and evenly spray 0.2 kg of EPDM rubber after drying, the EPDM rubber is EPDM rubber particles with a particle size of 40 mesh, and obtain the finished product after drying.

[0062] Preparation Example 6: This preparation example differs from Preparation Example 4 in that:

[0063] Step I: one end of the glass fiber is dipped in ethyl cellulose solution, the ethyl cellulose solution is a 1% ethyl cellulose ethanol solution, the ethanol is anhydrous ethanol with a mass fraction of 99%, and the length of the end of the glass fiber dipped in ethyl cellulose is 0.2 mm; then the surface of the cutter is dipped in ethyl cellulose solution, and then the glass fiber is cut, and the glass fiber is quickly dried after cutting to obtain 6 mm long glass fiber chopped strands;

[0064] Step II: 1 kg of glass fiber chopped strands are placed in 5 kg of water containing amino-modified elastic particles, 2 kg of amino-modified elastic particles are placed in the 5 kg of water, and the amino-modified elastic particles are selected from the amino-modified elastic particles prepared in Preparation Example 3, and then the water is filtered out, and the glass fiber chopped strands loaded with amino-modified elastic particles are heated to 90° C. for heat treatment for 5 min, and then cooled to obtain loaded glass short fibers;

[0065] Step III: 0.4 kg of acrylic resin melt is evenly sprayed on the surface of 1 kg of loaded glass short fibers, and after drying, 0.5 kg of EPDM rubber is evenly sprayed on the surface. The EPDM rubber is EPDM rubber particles with a particle size of 40 meshes, and the finished product is obtained after drying.

[0066] Example

[0067] The stearic acid in the following raw materials was purchased from Henan Tinian Chemical Products Co., Ltd.; the softener was purchased from the natural rubber softener, naphthenic oil 4006 produced by Hengshui Diyi Petrochemical Co., Ltd.; other raw materials and equipment were all commercially available.

[0068] Embodiment 1: A rubber bead protector for all-steel giant engineering machinery radial tire:

[0069] 55kg natural rubber, 49kg cis-1,4-butadiene rubber, 65kg carbon black, 3kg zinc oxide, 1.5kg stearic acid, 4.5kg antioxidant, 0.8kg protective wax, 4kg glass staple, 3kg softener, 3kg leveler, 2.6kg sulfur, 1.1kg accelerator, 0.3kg anti-scorch agent, 0.5kg anti-reversion agent; 45kg low cis polybutadiene rubber and 4kg liquid polybutadiene rubber in cis-1,4-butadiene rubber; 1.8kg antioxidant 4020, 1.2kg antioxidant RD, and 1.5kg cerium stearate in the antioxidant; the glass staple is the rubber impregnated modified glass staple prepared in Preparation Example 4; the leveler is the leveler 40MSF; the accelerator is 0.6kg accelerator NS and 0.5kg accelerator DZ; the anti-scorch agent is the anti-scorch agent CTP; the anti-reversion agent is the anti-reversion agent HTS;

[0070] The preparation method is as follows:

[0071] S1. Mix natural rubber, butadiene rubber and carbon black in an internal mixer and mix them. The filling factor is 75%. The mixing is carried out for 3 minutes at a pressure of 0.6 MPa. The rubber is discharged at a temperature of 160°C. The rubber is made into a film with a thickness of 5 mm by an open mixer. After the film is left at room temperature for 8 hours, a mixed masterbatch is obtained.

[0072] S2, zinc oxide, stearic acid, antioxidant, protective wax, glass short fiber, softener, homogenizer and the first-stage masterbatch prepared in S1 are mixed, added into an internal mixer for mixing, the filling factor is 70%, the mixing time is 3 minutes, the pressure is 0.6 MPa, and the rubber is discharged at a temperature of 160°C; the rubber is made into a film with a thickness of 5 mm by an open mixer, and the rubber is left at room temperature for 8 hours to obtain a second-stage masterbatch;

[0073] S3. Add the two-stage mixed masterbatch prepared in S2 into an internal mixer for internal mixing, keep the filling factor at 75% and the pressure at 0.2MPa, add sulfur, accelerator, anti-scorch agent and anti-vulcanization reversion agent after breaking the rubber for 30s, and mix the rubber for 2min at a pressure of 0.2MPa. Discharge the rubber when the temperature reaches 100℃; use an open mixer to prepare a film with a thickness of 5mm, and after the film is left at room temperature for 8h, obtain a finished product of the sub-mouth protective rubber.

[0074] Embodiment 2: This embodiment differs from Embodiment 1 in that:

[0075] 40kg natural rubber, 43kg cis-1,4-butadiene rubber, 60kg carbon black, 2kg zinc oxide, 1kg stearic acid, 3kg antioxidant, 0.5kg protective wax, 4kg glass staple, 2kg softener, 2kg homogenizer, 2kg sulfur, 1kg accelerator, 0.2kg anti-scorch agent, 0.5kg anti-vulcanization reversion agent; 38kg low cis polybutadiene rubber in cis-1, 5kg liquid polybutadiene rubber; 1kg antioxidant 4020, 1kg antioxidant RD, 1kg cerium stearate in the antioxidant; the glass staple is the rubber impregnated modified glass staple prepared in Preparation Example 5; 0.5kg accelerator NS and 0.5kg accelerator DZ in the accelerator;

[0076] The preparation method is as follows:

[0077] S1. Mix natural rubber, butadiene rubber and carbon black in an internal mixer and mix them. The filling factor is 80%. Mix them for 4 minutes at a pressure of 0.6 MPa. Discharge the rubber at a temperature of 150°C. Use an open mixer to make a film with a thickness of 10 mm. After the film is left at room temperature for 8 hours, a mixed masterbatch is obtained.

[0078] S2, zinc oxide, stearic acid, antioxidant, protective wax, glass short fiber, softener, homogenizer and the first-stage mixing masterbatch prepared in S1 are mixed, and added into an internal mixer for mixing, with a filling factor of 75%, a mixing time of 4 minutes, a pressure of 0.6 MPa, and the rubber is discharged at a temperature of 150°C; the rubber is made into a film with a thickness of 10 mm by an open mixer, and the rubber is left at room temperature for 8 hours to obtain a second-stage mixing masterbatch;

[0079] S3. Add the two-stage mixed masterbatch prepared in S2 into an internal mixer for internal mixing, keep the filling factor at 80% and the pressure at 0.2MPa, add sulfur, accelerator, anti-scorch agent and anti-vulcanization reversion agent after breaking the rubber for 30s, and knead the rubber for 1min at a pressure of 0.2MPa. Discharge the rubber when the temperature reaches 95℃; use an open mixer to prepare a film with a thickness of 10mm, and after the film is left at room temperature for 8h, a finished product of the sub-mouth protective rubber is obtained.

[0080] Embodiment 3: This embodiment differs from Embodiment 1 in that:

[0081] 60kg natural rubber, 65kg butadiene rubber, 70kg carbon black, 3kg zinc oxide, 2kg stearic acid, 6kg antioxidant, 1kg protective wax, 5kg glass staple fiber, 4kg softener, 4kg leveler, 4kg sulfur, 2kg accelerator, 0.5kg scorch retarder, 1kg anti-vulcanization reversion agent; 50% low cis polybutadiene rubber and 10% liquid polybutadiene rubber in butadiene rubber; 2g antioxidant 4020, 2kg antioxidant RD and 2g cerium stearate in the antioxidant; the glass staple fiber is the rubber impregnated modified glass staple fiber prepared in Preparation Example 6; the leveler is leveler 40MSF; the accelerator is 1g accelerator NS and 1g accelerator DZ.

[0082] Embodiment 4: This embodiment differs from Embodiment 1 in that:

[0083] The glass short fibers in the raw materials of the sub-mouth protective glue are replaced by glass fiber chopped strands of equal quality, and the glass fiber chopped strands are alkali-free glass fiber chopped strands with a length of 5 mm.

[0084] Embodiment 5: This embodiment differs from Embodiment 1 in that:

[0085] The glass short fiber is a rubber impregnated modified glass short fiber. The preparation process of the rubber impregnated modified glass short fiber is as follows:

[0086] Step I: The glass fiber strands are cut to obtain glass fiber chopped strands with a length of 4 mm.

[0087] Embodiment 6: This embodiment differs from Embodiment 1 in that:

[0088] The glass short fiber is rubber impregnated modified glass short fiber. The preparation process of rubber impregnated modified glass short fiber is as follows:

[0089] In step I, the ethyl cellulose solution is replaced with an equal mass of sodium carboxymethyl cellulose solution in the raw material, and the mass fraction of the sodium carboxymethyl cellulose solution is 1%.

[0090] Embodiment 7: This embodiment differs from Embodiment 1 in that:

[0091] The glass short fiber is rubber impregnated modified glass short fiber. The preparation process of rubber impregnated modified glass short fiber is as follows:

[0092] Step I: Cut 1 kg of glass fiber into short strands of 4 mm in length, and then soak them in 5 kg of ethyl cellulose solution for 2 minutes. The ethyl cellulose solution is a 1% ethyl cellulose ethanol solution, and the ethanol is anhydrous ethanol with a mass fraction of 99%. After taking out the short strands, dry and disperse them immediately to obtain 4 mm long glass fiber chopped strands.

[0093] Embodiment 8: This embodiment differs from Embodiment 1 in that:

[0094] The glass short fiber is rubber impregnated modified glass short fiber. The preparation process of rubber impregnated modified glass short fiber is as follows:

[0095] Step II: Soak the chopped glass fibers in water containing amino-modified elastic particles, filter out the water, dry at room temperature 25°C, and then cool to obtain loaded glass fibers.

[0096] Embodiment 9: This embodiment differs from Embodiment 1 in that:

[0097] The glass short fiber is rubber impregnated modified glass short fiber. The preparation process of rubber impregnated modified glass short fiber is as follows:

[0098] Step II: Mix and stir the chopped glass fibers and the amino-modified elastic particles, then heat the chopped glass fibers loaded with the amino-modified elastic particles to 85° C. for heat treatment, and then cool to obtain loaded glass short fibers.

[0099] Embodiment 10: This embodiment differs from Embodiment 1 in that:

[0100] The glass short fiber is rubber impregnated modified glass short fiber. The preparation process of rubber impregnated modified glass short fiber is as follows:

[0101] Step I: one end of the glass fiber is dipped in ethyl cellulose solution, the ethyl cellulose solution is a 1% ethyl cellulose ethanol solution, the ethanol is anhydrous ethanol with a mass fraction of 99%, and the length of the end of the glass fiber dipped in ethyl cellulose is 0.1 mm; then the surface of the cutter is dipped in ethyl cellulose solution, and then the glass fiber is cut, and the glass fiber is quickly dried after cutting to obtain 4 mm long glass fiber chopped strands;

[0102] Step II: 0.3 kg of acrylic resin melt is evenly sprayed on the surface of 1 kg of glass fiber chopped strands. The acrylic resin melt is obtained by hot melting thermoplastic acrylic resin solid particles. After drying, 0.4 kg of EPDM rubber is evenly sprayed on the surface. After drying, a finished product is obtained.

[0103] Embodiment 11: This embodiment differs from Embodiment 1 in that:

[0104] The glass short fiber is rubber impregnated modified glass short fiber. The preparation process of rubber impregnated modified glass short fiber is as follows:

[0105] In step III, the raw material is replaced with an equal mass of polyvinyl alcohol liquid to replace the acrylic resin melt, the concentration of the polyvinyl alcohol liquid is 10%, and the degree of polymerization of the polyvinyl alcohol is 50,000.

[0106] Embodiment 12: This embodiment differs from Embodiment 1 in that:

[0107] The glass staple fiber is a modified glass staple fiber, that is, it has not been modified by EPDM rubber. The preparation process is as follows:

[0108] Step I: one end of the glass fiber is dipped in ethyl cellulose solution, the ethyl cellulose solution is a 1% ethyl cellulose ethanol solution, the ethanol is anhydrous ethanol with a mass fraction of 99%, and the length of the end of the glass fiber dipped in ethyl cellulose is 0.1 mm; then the surface of the cutter is dipped in ethyl cellulose solution, and then the glass fiber is cut, and the glass fiber is quickly dried after cutting to obtain 4 mm long glass fiber chopped strands;

[0109] Step II: 1 kg of glass fiber chopped strands are placed in 5 kg of water containing amino-modified elastic particles, 2 kg of amino-modified elastic particles are placed in the 5 kg of water, and the amino-modified elastic particles are selected from the amino-modified elastic particles prepared in Preparation Example 1, and then the water is filtered out, and the glass fiber chopped strands loaded with amino-modified elastic particles are heated to 85° C. for heat treatment for 5 min, and then cooled to obtain loaded glass short fibers;

[0110] Step III: 0.3 kg of acrylic resin melt is evenly sprayed on the surface of 1 kg of loaded glass short fibers. The acrylic resin melt is obtained by hot melting thermoplastic acrylic resin solid particles, and the finished product is obtained after drying.

[0111] Embodiment 13: This embodiment differs from Embodiment 1 in that:

[0112] The glass staple fiber is a rubber impregnated modified glass staple fiber. In the preparation process of the amino-modified elastic particles in the rubber impregnated modified glass staple fiber:

[0113] The swellable chitosan is replaced by water-soluble chitosan of equal mass in the raw materials. The water-soluble chitosan is a carboxymethyl chitosan aqueous solution with a concentration of 2%.

[0114] Embodiment 14: This embodiment differs from Embodiment 1 in that:

[0115] The glass staple fiber is a rubber impregnated modified glass staple fiber. In the preparation process of the amino-modified elastic particles in the rubber impregnated modified glass staple fiber:

[0116] No EVA particles were added to the swelling chitosan solution.

[0117] Embodiment 15: This embodiment differs from Embodiment 1 in that:

[0118] The antioxidant in the raw materials is replaced by antioxidant 4020 of equal mass to replace antioxidant RD and cerium stearate.

[0119] Comparative Example

[0120] Comparative Example 1: The difference between this comparative example and Example 1 is that:

[0121] No short glass fibers are added to the raw materials.

[0122] Comparative Example 2: The difference between this comparative example and Example 1 is that:

[0123] The liquid polybutadiene rubber in the butadiene rubber is replaced by the same mass of octylphenol formaldehyde tackifying resin in the raw materials.

[0124] Performance testing

[0125] 1. Mechanical strength test

[0126] Finished sub-mouth protective rubbers were prepared by the preparation methods of Examples 1-15 and Comparative Example 1-2, respectively. The sub-mouth protective rubbers were vulcanized at 143°C for 120 min to obtain samples. With reference to GB / T528-2009 Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber, 100% constant force tensile test was performed on the samples prepared in Examples 1-10, 12-16 and Comparative Example 1-2, and the data were recorded; 300% constant force tensile test was performed on the sample prepared in Example 1-3; tensile strength test was performed on the samples prepared in Example 1-15 and Comparative Example 1-2; and elongation at break was tested on the sample prepared in Example 1-3, and the data was recorded.

[0127] With reference to GB / T 531.1-2008 Test method for indentation hardness of vulcanized rubber or thermoplastic rubber Part 1: Shore A hardness tester method (Shore hardness), the samples prepared in Examples 1-4 and Comparative Examples 1-2 were tested for Shore A hardness and the data were recorded.

[0128] The tear strength of the samples prepared in Examples 1 to 3 was tested with reference to GB / T 529-2008 Determination of tear strength of vulcanized rubber or thermoplastic rubber (rectangular), and the data was recorded.

[0129] With reference to GB / T 1689-1998 Determination of wear resistance of vulcanized rubber (using an Akron abrasion machine), the Akron abrasion amount of the samples prepared in Examples 1-4 and Comparative Examples 1-2 was tested and the data were recorded.

[0130] 2. Performance test after thermal aging

[0131] Finished sub-mouth protective glue was prepared by the preparation methods of Examples 1-15 and Comparative Example 1-2 respectively, the sub-mouth protective glue was vulcanized at 143°C for 120 min, and then aged at 100°C for 72 h. Similarly, the 100% constant force tensile test was performed on the aged samples prepared in Examples 1-3 and Comparative Example 1-2 with reference to the above-mentioned testing method; the tensile strength test was performed on the aged samples prepared in Examples 1-10, 12-16 and Comparative Example 1-2; the elongation at break test was performed on the aged sample prepared in Example 1-3; the Shore A hardness test was performed on the aged sample prepared in Example 1-3, and the data was recorded.

[0132] Table 1 Performance test table of unaged samples

[0133]

[0134]

[0135] Table 2 Thermal aging performance test table

[0136]

[0137]

[0138] 3. Performance test after water aging

[0139] The finished product of the sub-mouth protective glue was prepared by the preparation methods of Examples 1-3, 6, 11, and 13 respectively, and the sub-mouth protective glue was vulcanized at 143° C. for 120 minutes, and then immersed in water for 24 hours. The tensile strength was also tested with reference to the above-mentioned test method, and the data was recorded.

[0140] 4. Scratch performance test

[0141] The finished product of the nozzle guard was prepared by the preparation methods of Examples 1-4, 12 and Comparative Examples 1-2, and the nozzle guard was vulcanized at 143°C for 120 min to obtain a sample. Sand and gravel particles with a particle size of 2-3 mm were sprayed onto the sample surface at a spray speed of 1 cm / s. After spraying for 12 hours, the 900 cm 2 The number of scratches on the sample surface (i.e. length 30cm, width 30cm, area 900cm 2 ), record the data.

[0142] Table 3 Water aging and scratch resistance test table

[0143] project Tensile strength / MPa Number of scratches Example 1 17.02 1 Example 2 16.97 3 Example 3 17.05 1 Example 4 / 9 Example 6 15.40 / Embodiment 11 15.45 / Example 12 / 6 Embodiment 13 14.12 / Comparative Example 1 / 16 Comparative Example 2 / 4

[0144] From Examples 1-3 and Tables 1, 2 and 3, it can be seen that the sub-mouth protective rubber has a higher tensile strength, a higher tensile strength, a higher elongation at break, a higher hardness, and a reduced wear, indicating that the finished sub-mouth protective rubber has a higher structural density, which gives it the advantages of high mechanical strength and good wear resistance; even after heat aging and water aging treatments, it still has good mechanical strength, which gives it a longer service life.

[0145] From Example 1 and Examples 4-16 and Tables 1, 2 and 3, it can be seen that the glass staple fibers in the raw materials of Example 4 are replaced by chopped glass fibers of equal mass. Compared with Example 1, the mechanical properties of the glass staple fibers prepared in Example 4 are worse than those in Example 1. This indicates that the glass staple fibers that have not been surface treated are not compatible with materials such as natural rubber and butadiene rubber, thereby affecting the mechanical properties.

[0146] During the preparation of the rubber-impregnated modified glass staple fibers in Example 5, no end-capping treatment was performed with the ethyl cellulose solution. Compared with Example 1, the mechanical properties of the sub-mouth protective glue prepared in Example 5 were slightly worse than those in Example 1; this indicates that without end-capping, the hydroxyl groups at both ends of the glass staple fibers easily attracted the amino-modified elastic particles and easily formed a linear connection structure, while a spherical structure can improve the mechanical properties of the finished product.

[0147] In the preparation process of the rubber-impregnated modified glass staple fibers in Example 6, the ethyl cellulose solution is replaced by an equal mass of sodium carboxymethyl cellulose solution. Compared with Example 1, the mechanical properties of the spout protective glue prepared in Example 6 are slightly worse than those in Example 1, and the reduction in tensile strength after water aging treatment is greater than the corresponding reduction in Example 1; this indicates that the sodium carboxymethyl cellulose solution is hygroscopic and can easily promote the water absorption of the spout protective glue during the water aging process, thereby easily affecting the strength of the finished spout protective glue; and after the sodium carboxymethyl cellulose solution is attached to the glass staple fibers, the carboxyl and hydroxyl groups of the sodium carboxymethyl cellulose solution are used to connect the glass staple fibers linearly, and the end-capping treatment with ethyl cellulose can make the glass staple fibers independently dispersed, and amino-modified elastic particles are attached to the outer peripheral surface to make them spherical, thereby increasing the contact area between the glass staple fibers and natural rubber and butadiene rubber, thereby improving the mechanical strength of the finished spout protective glue and extending its service life.

[0148] In the preparation process of the rubber-impregnated modified glass staple fibers in Example 7, the glass fiber chopped strands were immersed in an ethyl cellulose solution. Compared with Example 1, the mechanical strength of the sub-end protective glue prepared in Example 7 was worse than that in Example 1. This indicates that under the viscosity of the ethyl cellulose solution, the surface of the glass fiber chopped strands is easily made hydrophobic and difficult to attract the amino-modified elastic particles, thereby affecting the adhesion of the amino-modified elastic particles to the surface of the glass fiber chopped strands and affecting the mechanical strength of the finished sub-end protective glue.

[0149] In the preparation process of the rubber-impregnated modified glass staple fibers in Example 8, step 2 was not subjected to heat treatment at elevated temperatures. Compared with Example 1, the mechanical strength of the sub-mouth protective glue prepared in Example 8 was inferior to that in Example 1. This indicates that the elevated temperature treatment can cause the EVA in the chitosan solution to melt, thereby more stably bonding the amino-modified elastic particles to the surface of the glass fiber chopped strands, thereby improving the elasticity, mechanical strength and wear resistance of the finished sub-mouth protective glue.

[0150] In the preparation process of the rubber-impregnated modified glass staple fibers in Example 9, the glass fiber chopped strands and the amino-modified elastic particles are directly mixed and stirred. Compared with Example 1, the mechanical strength of the rubber stopper prepared in Example 9 is much worse than that in Example 1, which indicates that direct mixing makes it difficult for the amino-modified elastic particles to be evenly dispersed and attracted to the glass fiber chopped strands. In the process of dispersion in water, the hydroxyl groups on the peripheral surface of the glass fiber chopped strands are combined with the amino groups in the amino-modified elastic particles, so that the amino-modified elastic particles can be evenly dispersed on the peripheral surface of the glass fiber chopped strands. In conjunction with the subsequent heating operation, the amino-modified elastic particles can be bonded to the surface of the glass fiber chopped strands, thereby increasing the contact area between the finished glass staple fibers and the natural rubber and butadiene rubber, so that the rubber stopper has higher mechanical strength and longer service life.

[0151] In the preparation process of the rubber-impregnated modified glass staple fibers in Example 10, amino-modified elastic particles were not loaded. Compared with Example 1, the mechanical properties of the spout protective rubber prepared in Example 10 were worse than those in Example 1. This indicates that the amino-modified elastic particles can increase the contact area between the glass staple fibers and natural rubber and butadiene rubber, thereby improving the mechanical strength of the finished spout protective rubber and extending its service life.

[0152] During the preparation of the rubber-impregnated modified glass staple fibers in Example 11, the acrylic resin melt was replaced with an equal mass of polyvinyl alcohol liquid. Compared with Example 1, the mechanical strength of the rubber spout guard prepared in Example 11 was worse than that in Example 11, and the degree of performance degradation after water aging was greater than the degree of performance degradation of the unaged Example 1. This indicates that although the polyvinyl alcohol liquid is viscous and can bond the EPDM rubber to the surface of the glass fiber chopped strands, polyvinyl alcohol is water-absorbent and water-soluble and is not resistant to water aging, which can easily affect the mechanical strength and service life of the rubber spout guard.

[0153] In Example 12, the surface of the glass staple fiber is not treated with EPDM rubber. Compared with Example 1, the mechanical strength of the sub-mouth protective rubber prepared in Example 1 is worse than that in Example 1. This indicates that the EPDM rubber particles can improve the compatibility of the glass staple fiber with natural rubber and butadiene rubber, thereby improving the mechanical strength of the finished sub-mouth protective rubber and extending its service life.

[0154] In the preparation process of amino-modified elastic particles in Example 13, the swellable chitosan is replaced by water-soluble chitosan of equal mass. Compared with Example 1, the mechanical strength of the sub-mouth protective glue prepared in Example 13 is worse than that in Example 1, and the tensile strength changes greatly after water aging. This indicates that when the amino-modified elastic particles are dispersed in water, chitosan dissolves, which easily affects the dispersion and uniform adhesion of the elastic particles on the surface of the glass fiber chopped strands, thereby affecting the mechanical strength of the finished sub-mouth protective glue; water-soluble chitosan is not resistant to water aging.

[0155] During the preparation of amino-modified elastic particles in Example 14, no EVA particles were added. Compared with Example 1, the mechanical strength of the sub-mouth protective glue prepared in Example 14 was worse than that in Example 1, which indicates that EVA particles can improve the structural density of the sub-mouth protective glue, thereby improving the mechanical strength and extending the service life.

[0156] In Example 15, the antioxidant 4020 is used to replace the antioxidant RD and cerium stearate with the same mass. Compared with Example 1, the mechanical strength of the sub-mouth protective glue prepared in Example 1 is worse than that in Example 1, which indicates that the combination of antioxidant 4020, antioxidant RD and cerium stearate can improve the mechanical strength of the sub-mouth protective glue.

[0157] It can be seen from Example 1 and Comparative Examples 1-2 and Tables 1, 2 and 3 that no glass short fibers are added to the raw materials of Comparative Example 1. Compared with Example 1, the mechanical strength of the sub-mouth protective glue prepared in Comparative Example 1 is worse than that in Example 1, indicating that the addition of glass short fibers can improve the mechanical strength of the sub-mouth protective glue.

[0158] In the comparative example 2, the liquid polybutadiene rubber in the butadiene rubber is replaced by the same mass of octyl phenolic tackifying resin in the raw material. Compared with Example 1, the mechanical strength of the spout protective rubber prepared in Comparative Example 2 is worse than that in Example 1, which indicates that the liquid polybutadiene rubber can improve the cross-linking structure density of the spout protective rubber, so that the finished spout protective rubber has higher mechanical strength and longer service life.

[0159] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A rubber bead protector for all-steel giant engineering machinery radial tire, characterized in that: The spout protection rubber comprises the following raw materials in parts by weight: 40-60 parts of natural rubber, 43-65 parts of butadiene rubber, 60-70 parts of carbon black, 2-3 parts of zinc oxide, 1-2 parts of stearic acid, 3-6 parts of antioxidant, 0.5-1 parts of protective wax, 4-5 parts of glass short fiber, 2-4 parts of softener, 2-4 parts of homogenizer, 2-4 parts of sulfur, 1-2 parts of accelerator, 0.2-0.5 parts of anti-scorch agent, and 0.5-1 parts of anti-vulcanization reversion agent; the glass short fiber is rubber impregnated modified glass short fiber; The rubber impregnated modified glass staple fiber is prepared by the following method: Step I: Dip one end of the glass fiber into the ethyl cellulose solution, then dip the surface of the cutter into the ethyl cellulose solution, and then cut the glass fiber. After cutting, dry quickly to obtain glass fiber chopped strands with a length of 3-6 mm. Step II: soaking the chopped glass fibers in water containing amino-modified elastic particles, filtering out the water, heating the chopped glass fibers loaded with amino-modified elastic particles to 80-90° C. for heat treatment, and then cooling to obtain loaded glass short fibers; Step III: spraying acrylic resin melt evenly on the surface of the loaded glass short fiber, the weight ratio of the loaded glass short fiber to the acrylic resin melt being 1:0.1-0.4, spraying EPDM rubber evenly after drying, the weight ratio of the loaded glass short fiber to the EPDM rubber being 1:0.2-0.5, and drying to obtain a finished product; The amino-modified elastic particles are prepared by the following method: The swellable chitosan is placed in dilute acetic acid and stirred to dissolve to obtain a solution; then EVA particles are added, the weight ratio of the solution to the EVA particles is 1:0.05-0.2, and the mixture is evenly dispersed to obtain a swellable chitosan solution; Weigh the polyimide resin particles and soak them in the swelling chitosan solution, then take out the polyimide resin particles and dry them to obtain the finished product.

2. The bead protection rubber for all-steel giant engineering machinery radial tire according to claim 1, characterized in that: The cis-1,4-diene rubber comprises the following raw materials in parts by weight: 40-50 parts of low-cis polybutadiene rubber and 3-5 parts of liquid polybutadiene rubber.

3. The bead protection rubber for all-steel giant engineering machinery radial tire according to claim 1, characterized in that: The antioxidant comprises the following raw materials in parts by weight: 1-2 parts of antioxidant 4020, 1-2 parts of antioxidant RD, and 1-2 parts of cerium stearate.

4. The bead protection rubber for all-steel giant engineering machinery radial tire according to claim 1, characterized in that: The accelerator comprises the following raw materials in parts by weight: 0.5-1 part of accelerator NS and 0.5-1 part of accelerator DZ.

5. The bead protection rubber for all-steel giant engineering machinery radial tire according to claim 1, characterized in that: The homogenizer is homogenizer 40-MSF.

6. The method for preparing the bead protection rubber for all-steel giant engineering machinery radial tire according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1. After mixing natural rubber, butadiene rubber and carbon black, the mixture is mixed, discharged, film is prepared and allowed to stand to obtain a mixed masterbatch; S2, mixing zinc oxide, stearic acid, antioxidant, protective wax, short glass fiber, softener, homogenizer and the first-stage mixed masterbatch prepared in S1, and preparing the second-stage mixed masterbatch through mixing, debonding, film preparation and standing; S3, the second stage mixed masterbatch is subjected to internal mixing, sulfur, accelerator, anti-scorch agent, anti-vulcanization reversion agent are added after the rubber is broken, and the finished product of the spigot protection rubber is obtained through rubber refining, rubber discharge, film preparation, and standing.

Images